python全栈开发- 前??能-迭代器

def func():
 　　print("呵呵")
print(func)
结果:
<function func at 0x1101e4ea0>

def func():
 　　print("呵呵")
print(func)
a = func # 把函数当成?个变量赋值给另?个变量
a() # 函数调? func()

def func1():
 　　print("呵呵")
def func2():
 　　print("呵呵")
def func3():
　　 print("呵呵")
def func4():
 　　print("呵呵")
lst = [func1, func2, func3]
for i in lst:
 　　i()

def func():
     print("吃了么")
def func2(fn):
     print("我是func2")
     fn() # 执?传递过来的fn
     print("我是func2")
func2(func) # 把函数func当成参数传递给func2的参数fn.

def func_1():
     print("这?是函数1")
     def func_2():
         print("这?是函数2")
     print("这?是函数1")
     return func_2
fn = func_1() # 执?函数1. 函数1返回的是函数2, 这时fn指向的就是上?函数2
fn() # 执?上?返回的函数    

def func1():
     name = "alex"
     def func2():
         print(name) # 闭包
     func2()
func1()
结果:
alex    

def func1():
     name = "alex"
     def func2():
         print(name) # 闭包
     func2()
     print(func2.__closure__) # (<cell at 0x10c2e20a8: str object at
0x10c3fc650>,)
func1()

def outer():
     name = "alex"
     # 内部函数
     def inner():
         print(name)
     return inner
fn = outer() # 访问外部函数, 获取到内部函数的函数地址
fn() # 访问内部函数    

def func1():
     def func2():
         def func3():
             print("嘿嘿")
     　　return func3
 　　return func2
func1()()()    

from urllib.request import urlopen
def but():
     content = urlopen("http://www.xiaohua100.cn/index.html").read()
     def get_content():
         return content
     return get_content
fn = but() # 这个时候就开始加载校花100的内容
# 后?需要?到这??的内容就不需要在执??常耗时的?络连接操作了
content = fn() # 获取内容
print(content)
content2 = fn() # 重新获取内容
print(content2)

l = [1,2,3]
l_iter = l.__iter__()
from collections import Iterable
from collections import Iterator
print(isinstance(l,Iterable)) #True
print(isinstance(l,Iterator)) #False
print(isinstance(l_iter,Iterator)) #True
print(isinstance(l_iter,Iterable)) #True

s = "我爱北京天安?"
c = s.__iter__() # 获取迭代器
print(c.__next__()) # 使?迭代器进?迭代. 获取?个元素 我
print(c.__next__()) # 爱
print(c.__next__()) # 北
print(c.__next__()) # 京
print(c.__next__()) # 天
print(c.__next__()) # 安
print(c.__next__()) # ?
print(c.__next__()) # StopIteration

for i in [1,2,3]:
 print(i)

lst = [1,2,3]
lst_iter = lst.__iter__()
while True:
     try:
         i = lst_iter.__next__()
         print(i)
     except StopIteration:
         break